<%@ Control Language="C#" autoeventwireup="true" %>
<table width="100%" class="containers">
<tr>
    <td width="50%" class="item">
        <asp:PlaceHolder ID="Left_Container" runat="server" />
    </td>
    <td width="50%" class="item">
        <asp:PlaceHolder ID="Main_Container" runat="server" />
    </td>    
</tr>
</table>